In a number of data processing applications fragments of data sent from a source system must be processed into a required data format on a target system.
In many instances it is desired to replicate a database on a target computer system from a database on a source system. This process may involve sending journal entries from the source database to allow updating of the target database. Databases may consist of one or more library, each of which contains one or more files, each file having one or more members. Each member consists of a table having one or more rows. A journal entry may contain an identifier of the library; file; file member and a row of changed data for the file member. This journal entry may be used by the target computer system to update its database.
It is important that database entries from a given table are updated in the correct sequence and that inter-related members are updated in the correct sequence. To ensure that journal entries are properly processed a receive process of the target computer system may compare an object name (library/file/member) with a database of objects stored on the target computer system. When a matching object is located the processing information associated with that object may be used to process the journal entry.
The traditional approach has been to transfer journal entries, store them and replicate the database utilising a single engine. This approach is slow and complex.
It would be desirable for a database replication system to meet the following requirements:                1. Ensure that journal entries are serialised by database member (at a minimum), and by any user specified groupings.        2. Support an extremely large number of database apply processes so that database I/O (input/output) can be easily managed.        3. Process journal entries in a way which minimises the amount of system I/O (e.g. paging) between the time the entries are obtained from the journal and the time it is applied to the replica database.        4. The functions support any type of data packets, not just journal entries, to allow for future extensions to other types of replication (e.g. object, stream files etc).        5. The system hides the complexity of the memory management functions from other components.        
It is an object of the present invention to provide a method and apparatus for information replication which meets these requirements or to at least provide the public with a useful choice.